Creation Of Non-Wired Communication Network, By Determining Local Topology Information From The Identifiers Of Communication Appliances

ABSTRACT

In order to create a non-wired network, a first communication appliance is provided with a list of identifiers of other communication appliances with which connections can be established. The first communication appliance determines information on the local topology of the non-wired communication network from the identifiers of the other communication appliances. The first communication appliance establishes a connection with the isolated, thus collected, partial networks and individual communication appliances, and integrates the same into the network.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is based on and hereby claims priority to ApplicationNo. PCT/EP2005/053763 filed on Aug. 2, 2005 and German Application No.10 2004 040 069.5 filed on Aug. 18, 2004, the contents of which arehereby incorporated by reference.

BACKGROUND

The present invention relates to a method for creating a non-wirelinecommunications network by determining local topology information fromthe identification codes of the communications devices.

Wireline network technology for the transmission of data between aplurality of communications devices involves a loss of mobility andtherefore also convenience. In contrast, non-wireline network technologyallows data to be transmitted over short distances without being subjectto mobility limitations. For this purpose the communications devices canconnect to one another spontaneously and autonomously.

In a first method, a first communications device is initially providedwith a list of the other communications devices to which it can connect.By proceeding step by step in the list or by manual manipulation, thefirst communications device decides to which other communications deviceit will make a request for a connection setup.

In a second method (Specification of the Bluetooth System, Version 1.2,Core) for creating a non-wireline network, a distinction is made betweena communications control device used for controlling communications, anda communications device which is controlled by the communicationscontrol device. In general, two communications control devices or twocontrolled communications devices cannot connect to each other. As acommunications control device can only control a limited number ofcommunications devices, this means that the size of a network is limitedby the user capacity of its communications control device. A largernumber of communications devices can be achieved by combining individualnetworks into a larger overall network. There are two possibilities forestablishing the necessary bridge connection between two communicationscontrol devices. One option is for a device to act as a communicationscontrol device in the first network and as a controlled communicationsdevice in the second network. Another option is to connect twocommunications control devices via a controlled communications device.This enables different network topologies to be achieved, such as atree, chain or mesh topology.

An implementation of a non-wireline network according to the secondmethod at Technion, Israel Institute of Technology in Haifa, requires,at startup of each device, information as to whether it is to beoperated as a communications control device or as a controlledcommunications device. By the positioning and the sequence in which thedevices are switched on, various topologies can then be created(http://www-comnet.technion.ac.il/˜cn9wO2). Such a network with a treetopology has been set up at the ETH Zurich(http://www.tik.ee.ethz.ch/˜beutel/bt node.html). The formationalgorithm is not known in greater detail.

The disadvantage of these methods is that a communications devicewishing to establish a connection has no information at its disposalconcerning the local topology of the network. This can result in anindividual communications device or entire subnetworks not beingincorporated in the overall network. Moreover, the creation of a networkcan only be achieved statically and does not therefore meet the dynamicrequirements for non-wireline transmission using a plurality ofcommunications devices.

SUMMARY

One possible object of the present invention is therefore to specify amethod whereby an overall network encompassing a plurality ofcommunications devices can organize itself and individual communicationsdevices and/or subnetworks not yet connected are incorporated when thisnetwork is created.

The inventors propose determining the local topology information. Thelocal topology information is determined from the identification codesof the communications devices. For this purpose a first communicationsdevice is given a list of identification codes of at least one secondcommunications device to which a connection is establishable. From theidentification codes, further communications devices that are connectedto the second communications device identified in the list can bedetermined. The first communications device requests a connection setupto at least one second communications device which is identified in thelist of identification codes and has no direct or indirect connection tothe first communications device or, according to the local informationfrom the list of identification codes, has no direct or indirectconnection to the first communications device. If the request issuccessful, a connection setup takes place.

Without limiting the generality of this term, communications devices areto be understood, for example, as PCs and computer peripherals, mobiledevices (laptops, handheld PCs, PDAs), telecommunications devices(mobile phones, ISDN systems), video and TV equipment, audio devices andhousehold appliances (washing machines, refrigerators). Said devices arenetworkable e.g. using IrDA, Bluetooth or WLAN modules.

According to an advantageous embodiment, a first communications deviceassigns second communications devices on the basis of theiridentification codes to, in each case, a group of communications deviceswhich are interconnected. The first communications device request aconnection to be set up to at least one second communications device ifsaid second communications device is not assigned to the same group ofcommunications devices as the first communications device. This ensuresfast and efficient determination of the local topology information,thereby enabling the network to be quickly created.

According to another advantageous embodiment, the local topologyinformation is determined by a communications control device from theidentification codes of communications devices, the term communicationsdevices being used here collectively for communications control devicesand controlled communications devices. A first communications controldevice is given a list of identification codes of at least one secondcommunications device to which a connection is establishable. From theidentification codes of the second communications devices, furthercommunications devices can be determined which are connected to thesecond communications device identified in the list. The firstcommunications control device requests a connection setup to at leastone second communications device which is identified in the list ofidentification codes and which has no direct or indirect connection tothe first communications device. If the request is successful, aconnection setup takes place.

Without limiting the generality of this term, communications controldevices are to be understood, for example, as a master device accordingto the Bluetooth communications protocol or a primary station accordingto the IrDA communications protocol. A controlled communications deviceaccordingly corresponds to a slave device according to the Bluetoothprotocol and a secondary station according to the IrDA protocol.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects and advantages will become more apparent andmore readily appreciated from the following description of the preferredembodiments, taken in conjunction with the accompanying drawings ofwhich:

FIG. 1 schematically illustrates an exemplary network topology with aplurality of master devices and slave devices,

FIG. 2 schematically illustrates the network topology from FIG. 1 afterexecution of the algorithm.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Reference will now be made in detail to the preferred embodiments,examples of which are illustrated in the accompanying drawings, whereinlike reference numerals refer to like elements throughout.

In FIGS. 1 and 2 the five shaded circles symbolize the master devicesand the fourteen white circles the slave devices. In this arrangementtwo master devices or two slave devices cannot connect directly to eachother. A connection between two master devices is only possible via aslave device which in this exemplary embodiment can be connected to upto two communications control devices. In general the number of deviceswhich a communications control device can control is limited fortechnical and/or administrative reasons. In the following description ofthe exemplary embodiment, “devices” is used as a collective term formaster devices and slave devices.

FIG. 1 shows a subnetwork with four master devices 1,2,3,4 and ten slavedevices 6,7,8,9,10,11,12,13,14,15, a subnetwork not connected to samecomprising one master device 5 and two slave devices 16,17, and anindividual slave device 18. The partial circle 20 represents the rangeof the master device 1. A continuous line 19 symbolizes an existingconnection between the devices, in the example for the line 19 aconnection between the master device 1 and the slave device 10.

In the identification codes (local names) of the slave devices arecontained the identifiers of the master devices to which the slavedevices are directly connected. As a first step, the master device 1 isgiven a list of the devices 6,7,2,8,9,3,10,15,5,16,17,18 within itsrange.

As additional information, the local name of the slave device 9 containsthe identifiers of the master devices 2 and 3 and the slave device 10the identifiers of the master devices 1 and 3. The local name of theslave device 6 contains the identifier of the master device 1, the localnames of the slave devices 7 and 8 the identifier of the master device2, the local name of the slave device 15 the identifier of the masterdevice 4 and the local names of the slave devices 16 and 17 theidentifier of the master device 5.

On the basis of this information, the master device 1 subdivides thedevices into three groups, interconnected devices being assigned to thesame group in each case. The first group contains the devices1,6,7,2,8,9,3,10, the second group the devices 5,16,17 and the thirdgroup the devices 4,15. The slave device 18 is not connected to anymaster device and is therefore not assigned to any group.

The first group contains the devices which are connected to the masterdevice 1. The second group has been recognized by the master device 1 asan isolated subnetwork comprising the interconnected devices 5,16,17.The devices 4 and 15 have been assigned by the master device 1 to thethird group and are therefore regarded by it as an isolated subnetwork.Because of the limited range of master device 1, only local topologyinformation is available to it. Therefore it is not recognizable to themaster device 1 that it is already connected indirectly to the slavedevice 15 and therefore to the third group.

The master device 1 successfully establishes a connection to slavedevice 18 in order to incorporate the individual slave device 18 intothe network. Master device 1 then successfully establishes a connectionto slave device 15 in order to assimilate the subnetwork determined bythe master device 1 into the network.

As a final step the master device 1 successfully establishes aconnection to slave device 17, which means that all the devices areinterconnected and the algorithm is therefore complete.

FIG. 2 shows the network topology from FIG. 1 after the above describedalgorithm has been executed. It can be seen from FIG. 2 that theindividual slave device 18 and the subnetwork comprising the devices5,16,17 have been incorporated in the network by the master device 1. Asthe slave device 11 lies outside the range of master device 1, themaster device 1 could not determine that it is already connected to theslave device 15 via the master device 4, thereby producing the meshbetween the master devices 1,3 and 4. The example shows that the degreeof meshing depends on the range of the master device.

A description has been provided with particular reference to preferredembodiments thereof and examples, but it will be understood thatvariations and modifications can be effected within the spirit and scopeof the claims which may include the phrase “at least one of A, B and C”as an alternative expression that means one or more of A, B and C may beused, contrary to the holding in Superguide v. DIRECTV, 358 F3d 870, 69USPQ2d 1865 (Fed. Cir. 2004).

1-7. (canceled)
 8. A method for creating a non-wireline communicationsnetwork, comprising: providing a first communications device with a listof identification codes of respective second communications devices towhich a connection with the first communications device isestablishable; identifying from each identification code allcommunications devices already connected to each second communicationsdevice; based on the communications devices connected to the secondcommunications device, determining if the second communications deviceis indirectly connected to the first communications device; for eachsecond communications device, sending a request for a connection setup,from the first communications device to the second communications deviceif the second communications device is not directly or indirectlyconnected to the first communications device; and setting up aconnection if the request is successful.
 9. The method as claimed inclaim 8, wherein the first communications device assigns aninterconnection group to each second communications device based on theidentification code of the second communications device, and the firstcommunications device sends the request for a connection setup, to thesecond communications device if the second communications device is notassigned to the same group as the first communications device.
 10. Themethod as claimed in claim 8, wherein the first communications deviceassigns an interconnection group to each second communications devicebased on the identification code of the second communications device,and the first communications device sends the request for a connectionsetup, to the second communications device if the second communicationsdevice is not assigned to the same group as the first communicationsdevice and the second communications device has less than apredetermined number of connections to other communications devices. 11.The method as claimed in claim 8, wherein the first communicationsdevice can be connected to no more than a limited number of secondcommunications devices.
 12. The method as claimed in claim 8, whereinthe first communications device is a communications control device, andeach communications control device is directly connected to onlycommunications device controlled by the communications control device.13. The method as claimed in claim 12, wherein the first and secondcommunications devices are configured according to Bluetooth CoreSpecification Version 1.2, each communications control devicecorresponds to a master and each communications device controlled by acommunications control device corresponds to a slave, and each slave hasa local name as its identification code.
 14. The method as claimed inclaim 8, wherein the first and second communications devices areconfigured according to Bluetooth Core Specification Version 1.2, thefirst communications device corresponds to a master, and in case of aconnection between first and second masters, the first master acts as aslave in the connection with the second master to form a master/slavebridge between the second master and a slave communications deviceconnected to the first master.
 15. The method as claimed in claim 10,wherein the first communications device can be connected to no more thana limited number of second communications devices.
 16. The method asclaimed in claim 15, wherein the first communications device is acommunications control device, and each communications control device isdirectly connected to only communications device controlled by thecommunications control device.
 17. The method as claimed in claim 16,wherein the first and second communications devices are configuredaccording to Bluetooth Core Specification Version 1.2, eachcommunications control device corresponds to a master and eachcommunications device controlled by a communications control devicecorresponds to a slave, and each slave has a local name as itsidentification code.
 18. The method as claimed in claim 15, wherein thefirst and second communications devices are configured according toBluetooth Core Specification Version 1.2, the first communicationsdevice corresponds to a master, and in case of a connection betweenfirst and second masters, the first master acts as a slave in theconnection with the second master to form a master/slave bridge betweenthe second master and a slave communications device connected to thefirst master.